The invention relates to a multi-layer body with two layers or layer systems and to a method for the production thereof.
Multi-layer bodies as a security element can be taken as known from the prior art and are widely used to protect bank notes, securities and identity documents against forgery or for the authentication of products. They are based on a combination of several functional layers, which may, for example, comprise optically variable elements (OVD=Optical Variable Devices), diffractive elements, partially metalized layers or printed features.
It is known to produce such multi-layer bodies by the sequential application of individual layers, building up the desired layer sequence. In order to obtain multi-layer bodies that are particularly forgery-proof, it is desirable to allow features of the individual layers to blend seamlessly into one another. In other words, the layers should be arranged as accurately as possible in register with one another. Where the multi-layer bodies are built up sequentially, however, this cannot always be achieved since the methods used to produce each individual layer are subject to tolerances in terms of the position of the layers relative to one another. As a result, the desired seamless transitions between the features cannot be achieved reliably, which has a negative effect on the anti-forgery security and the optical appearance of such a multi-layer body.
By register or register accuracy is meant the accurately positioned arrangement of superimposed layers relative to one another, maintaining a desired positional tolerance.